Hair waving heater



March 28,1939, A. M. POYNIATOFF' 2,152,359

nAm wAvme HEATER Filed June 20, 1936 2 Sheets-Sheet 1 INVENTOR. 4/exa/70er/W. flank/off A TTORNEY 7. -qegree.5 E

March 28,1939. A. M. PONIATCFF 2,152,359

.HAIR WAVING HEATER per/.00, I

ATTORNEYS.

Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE Application June 20,

4 Claims.

This invention relates generally to the construction of electrical heaters such as are employed in the permanent waving of hair, and to permanent hair waving methods making use of such devices.

In the permanent waving of hair, such as is carried out in commercial beauty parlors, it has been common to employ so-called electrical heaters, to supply the requisite heat for carrying out a steaming operation. Heaters such as have been employed in the past have been subject to certain inherent disadvantages. The most serious disadvantage has been the lack of proper control of the heat developed. Thus with a heater having an electrical heating element wound with conventional nichrome wire, the temperature attained during a period of pre-heat cannot I be properly controlled, and may become excessive or insuflicient' for proper application to the wound hair. Even after a period of pre-heat; application of a conventional heater to a wound strand of hair may not immediately result in vaporization of water or hair waving solution, although at the end of the steaming period the hair may perature.

The incorporation of a thermostatic switch with a conventional hair waving heater, may result in some improvement with respect to safety. However, where a period of pre-heat is employed, the use of a thermostatic switch results in interruption of the current supply during the initial part of the steaming period, due to the time lag inevitably involved in a device of this character,

:with the result that the hair is not brought to a steaming temperature until the latter part of the heating current.

It is a further object of the invention to pro-' vide a novel method for carrying out a steam operation in permanent hair waving, whereby optimum results are secured in lending perma-.

be'heated to an excessive and injurious tem- It is an object of the present invention to pro- 1936, Serial N0. 86,293

nency to the wave, and in securing uniform results.

Further objects of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth in detail in conjunction with the accompanying drawings.

Referring to the drawings;

Fig. 1 is a side elevational view showing a heat transferring metallic member, used in conjunction with a Croquignole hair waving heater incorporating the present invention.

Fig. 2 is an end view of the part shown in Fig. 1.

Fig. 3 is a side elevational View of a heating element'to be used with the member of Fig. 1, with parts broken away. 7

Fig. 4 is a side elevational View of the member shown in Fig. 3.

Fig. 5 is a side elevational view of a back member of shell, for use with the member and heating element of Figs. 1 and 3.

Fig. 6 is a cross-sectional detail taken along the line 6-6 of Fig. 5.

Fig. 7 is a cross-sectional view, showing the parts of Figs. 1 to 6 inclusive assembled to form a heating unit.

Fig. 8 is an end view showing a complete Croquignole heater utilizing two units as shown in Fig. .7, and applied to a strand of wound hair.

Fig. 9'is a side elevational view, partly in crosssection, and showing an internally heated curler, incorporating the invention.

Fig. 10 is a cross-sectional detail, taken along the line l0-'-I0 of Fig. 9.

Figgll is a view showing curves illustrating performance of the device described with reference to Figs. 1 to 8 inclusive.

Referring first to the Croquignole type of heater, illustrated in Figs. 1 to 8 inclusive, I have shown a pair of arcuated heating units it, to which the handles II are secured. The handles have a pivotal connection I2, and a spring i3 is associated with thispivot, in order to urge the units it in opposite directions upon the sides of a wound strand of hair.

The detailed construction for each of the units l0, can be best understood by referring to Figs. 1 to 7 inclusive. The inner face or shell portion of each unit is formed of a piece of sheet metal l4, made of suitable material such as aluminum or aluminum alloy. The outer face of each unit is formed of a piece of sheet metal l6 which islikewise bent to arcuate form, and which is adapted to be engaged by the crimped edges ll of the sheet metal member l4, to form what canbetermed a closed casing or sheath. Adjacent theinner face of member l4, there is an electrical heating element 18.

While the heating element 18 may vary as to details of construction, the arrangement illustrated consists of a sheet of insulating material l9, formed for example of mica. Upon this sheet of insulating material there is wound a resistance wire 2 i. Relatively thin sheets of insulating material 22 and 23, as for example sheets of mica, cover the faces of the resistance Wire, and this assembly is then enclosed within a folded sheet metal casing 24.

The heating element l8 occupies only a part of the space between the members I4 and l 6. The remainder of this space is occupied by a packing 26 of heat insulating material, such as asbestos. In order to insure relatively good heat transfer between the wire 2| and the secondary shell 24, and between the secondary shell and the member l4, the packing 25 is arranged to exert considerable pressure upon the heating element I8, whereby the casing 24 is maintained compressed, and whereby this casing is also pressed upon the inner face of member 14. It will be noted that heat from both faces of the resistance wire M is transferred to the metal casing 24, and conducted from this casing to the shell portion I4.

Instead of using conventional nichrome resistance wire, I employ a ballast wire, that is, a wire having a substantial positive temperature resistance co-efiicient. For example certain wire formed of nickel and iron alloy has been found to give good results, and affords a temperature ;resistance co-efficient of about 0.0061 (centigrade scale). This is about 47 times greater than the temperature resistance co-eflicient of nichrome Wire, which is about 0.00013.

Any suitable expedient can be employed for securing the handles H to the heating unit I0. For example members l4 and I5 can be provided with complementary cupped extensions 28 and 29, and which extend into the handles H. The space between extensions 28 and 29 can accommodate the lead wires 32, from the heating element.

The heating elements are designed with proper regard to the voltages to be employed, and with respect to the precise type of performance desired. For example the initial wattage consumption can be in the neighborhood of 80 watts, when the resistance wire is at atmospheric temperature. As the wire attains an elevated temperature, the wattage consumption is automatically reduced, because of the accompanying increase in resistance. Therefore heaters of such construction can be designed in such a manner that when suspended in the air with current being supplied, they will attain an equilibrium temperature approximating that desired at the end of a preheating operation.

A ,Croquignole heater of the type described is intended to be used in conjunction with a conventional Croquignole curler 34 and protector 35. In preparing a head of hair for a waving operation, protectors are clamped on flattened strands near the scalp and then each strand is wound upon a curler, with the curlers being finally mounted upon the protectors. The wound strand is moistened with hair waving solution, 2. moistened pad 36 is applied over the wound hair, and then the heater is clipped upon the assembly, as shown in Fig. 8.

A better idea of the method carried out by the use of the heater described above, can be had by examining the curves shown in Fig. 11. Curve I represents the temperature of the resistance wire; curve 2 the temperature of the metallic members l4; curve 3 the wattage consumption of the heating element; and curve 4 the temperature of the hair, during a steaming operation, taken at a point intermediate the curler upon which the hair is wound and the metallic members M. The left-hand portions of these curves represent a pre-heating operation before the heater is applied to a curler, while the right-hand portions represent a steaming or waving period. Note that during the pre-heating operation curve I rises rapidly and then flattens outtowards the end of the pre-heating operation. Curve 2, representing the temperature of the metallic elements l4, likewise rises rapidly, and then fiattens out towards the end of the pre-heating operation. Due to the relatively eflicient transfer of heat between the resistance wire and the metallic members M, the temperature differential between curves I and 2 is not excessive, and in the curves illustrated, does not amount to more than about F. at the end of the pre-heating operation. Curve 3, representing the wattage consumption, starts at a relatively high value near 80 watts, and then drops off rapidly as the temperature of the resistance wire increases. It likewise flattens out near the end of the preheating operation, representing clearly the fact that at the end of the pre-heating operation the heater is approximately in a state of temperature equilibrium.

Immediately upon applying the heater to a moistened strand of hair, Wound upon a curler, curve 2 drops down rapidly due to the chilling effect of the hair waving solution upon the metallic members l4. metallic members I4 is closely correlated with a corresponding drop in the temperature of the heating wire, and the drop in temperature of the heating wire causes a corresponding rise in curve 3, representing an immediate increase in wattage consumption. Thus the chilling effect of placing the heater into contact with a wound strand of hair is immediately accompanied by a compensating increase in heat developed. All of these changes occur within the initial part of the steaming period, and with the curves of Fig. 11, reach a state of virtual equilibrium in less than four minutes. Due to the heat stored in the metallic members l4, and in the inner secondary shell 24, at the end of the pre-heating operation, and also because of the immediate increase in wattage consumption, temperature of hair immediately rises from atmospheric to a vaporizing temperature of approximately 212 F., with maintenance of this temperature for the majority of the steaming operation, The latter part of curve 2 illustrates the fact that after a considerable part of the moisture has been evaporated, the metallic elements l4 gradually rise in temperature. However, such a rise in temperature is off-set by an automatic decrease in the wattage consumption, represented by the downward sloping of curve 3, which is caused by a gradual increase in the temperature of the heating wire and which prevents the temperature of members M from becoming excessive.

Heat treatment of the wound hair as described above is conducive to imparting the desired permanency to the wave, and in producing uniformly good results in successive waving operations. Utmost safety is afforded, because of the absence This drop in temperature of the of thermostatic switches and like contacting means.

The purpose of the insulating packing 26 is to maintain a high temperature differential between the element l8 and the outer shell portion l6.

Thus shell portion I6 is maintained at relatively low temperatures, enabling the use of a finishing lacquer or enamel to coat its outer surface. Likewise heat stored in shell portion l6 does'not greatly influence the automatic current control obtained in response to temperature variations of the inner metallic member or shell portion I4.

In connection with the heater described above, it is desirable to make use of heat stored during the pre-heating period, to effect rapid and initial vaporization of moisture. A conventional Croquignole heater, when applied to a moistened wound strand after a pre-heating operation contains an insufiicient amount of efiective stored heat to of itself start vaporization of moisture (carried by the pad and wound hair). I For example where about 8 B. t. u. are imparted to the hair and curler assembly'for a waving operation,

to form the inner shell portions l4, and the elec- I trical element sheath 24, with suflicient mass so that after a preheating operation there is sufficient effective stored heat to of itself commence vaporization of moisture when the heater is applied to the wound hair. For example where about 8 B. t. u. is being used for the complete waving period, at least about 1 B. t. u. or about 2 B. t. u. are made available as effective stored heat. Thus with such a heater effective stored heat serves to commence vaporization of moisture when the heater is applied, and additional heat supplied by the wattage consumption continues vaporization. In other words about 18% or more of the total heat requirement, is supplied at the beginning of the waving period, as effective stored heat.

My invention can be applied to other electrical heating equipment where current control is desired in response to temperature changes. For example in Figs. 9 and 10, it has been applied to a curler having an internal heater. Thus in this instance the metal curler body 38 has an axial opening 39, to receive the heating element 4|. Element ll consists of a refractory rod 42 having ballast wire 43 wound upon the same. The terminals of the ballast wire connect with the terminal connectors 44, carried by the mounting means 46, Mica insulation 41 separates the Wire 43 from direct electrical connection with the body of the curler, and clearance is reduced to a minimum, whereby there is good conduction of heat between the wire and the body of the curler. With a minimum amount of clearance, the wire tends to expand when heated, to press against the mica insulation.

A curler as shown in Figs. 9 and 10 is not preheated, before the strand of hair to be waved is wound upon the same. After the strand of hair has been wound upon the curler, current is applied, and since at that time the wire 43 is sumption is initially relatively high, to quickly heat the'curler to a steaming temperature. As the temperature of the curler increases the temperature of the wire 43 increases, thus causing an automatic reduction in wattage consumption, until vaporization of the hair waving solution commences. Thus initial steaming of the hair is accelerated, and toward the end of the steaming operation an increase in the temperature of the curler is offset by a further decrease in wattage consumption. A typical curve plotted with respect to wattage consumption would show an initial load of say watts, which would decrease rapidly to say 12 watts when the solution starts to vaporize.

The'invention can also be applied to heaters adapted for the spiral type of waving, in substantially the same manner as described for Figs. 1 to 8 inclusive. In fact the same heater illustrated in these figures can be clipped over hair wound upon a spiral type curler, with possibly a change in the disposition of the handles, to facilitate maintaining the curlers in a position extending outwardly from the head, instead of parallel thereto as in Croquignole waving.

I claim:

1. In a hair waving method, characterized by the use'of a metallic member adapted to be engaged with a wound strand of moistened hair and also adapted to be heated by an electrical resistance element, the step of pre-heating said metallic member out of engagement with the hair and with a graduated control of wattage consumption, whereby during the preheating period the wattage consumption is reduced to a substantial degree, applying the pre-heating metallic member to the moistened hair strand in order to commence a steaming period, causing the amount of heat stored in said metallic member to be of such amount that its temperature immediately following application to the hair is not reduced below 212, causing such reduction of temperature to be immediately reflected in an increase in the wattage consumption of the heating element and then permitting the metallic member to remain in engagement with the hair to complete the steaming operation, with a graduated reduction in wattage consumtion of the heating element towards the end of the steaming operation.

2. In a hair waving method, characterized by at atmospheric temperature, the wattage conthe use of a heater having a metallic member for engagement with a moistened strand of hair and heated by an electrical resistance element,

the step of pre-heating the metal member out of engagement with the hair and by current flow through said element, causing the pre-heating to plied to a moistened strand of wound hair, an

electrical heating element adjacent the other face of said member, said element being formed of a ballast resistor wire and having metal walls covering both faces of the same, said metal walls being in good heat conductive relationship with said metallic member.

4. In a hair waving heater, a metallic member adapted to have one face of the same applied to a moistened strand of wound hair, an electrical heating element adjacent the other face of said member, said element comprising a sheet of'insulating material, ballast resistor wire wound upon said sheet, and .a flat sheet metal casing serving to enclose said wound wire, one side of said casing being in direct physical engagement with said member, and means for continuously compressing said casing and for pressing the casing against said member, whereby thewire is in good heat conducting relationship with both sides of said casing and whereby said casing is in good heat transferring relationship with said metallic member.

ALEXANDER M. PONIATOFF. 

